This campsite is everything. First, it’s in Boulder County, about 40 minutes up Flagstaff Road from downtown Boulder. It’s one of the rare places to camp in the Boulder area; there are no actual campgrounds the city limits.
Second, it’s a peaceful hidden gem with minimal traffic. You may very well be the only camper here. Even on camp-crazy days like Memorial Day weekend, the trailhead’s rarely busy.
Third, it’s totally free.
Gross Reservoir, tucked in a scenic canyon, is our favorite secret camping spot close to home — so good that we almost didn’t share. But here we are. You lucky dog.
Before you set out on a camp-cation to Gross Reservoir, there are some things you need to know.
Gross Res is a stunning alpine body of water that is open to the public for free. You can go fishing, hiking, camping, paddling and picnicking here; take out a boat, too, but no motors allowed.
Likewise, camping is primitive. There are no RV hookups. This is a rugged spot for tents, but make sure you’re in the right spots.
Gross Reservoir is perched at 7,500 feet above sea level, located above Boulder along the South Boulder Creek Drainage. The cold-water reservoir has 440 acres of surface area, some that stretch out into isolated “fingers.” The lake itself gets deep (300 feet). Gross boasts 10 to 14 miles of shoreline (depending on who you ask).
Surrounding the water, you will see granite outcroppings, snowy mountaintops in the distance and plenty of pine trees. The reservoir, formed by an impressive, 340-foot-high concrete dam on the creek, is nestled into the foothills. The water here comes from the western slope.
Visitation details: Gross Reservoir is open year-round sunrise to sunset, but specific activities have limited windows. The west side is closed late fall through early spring. The lake is open to boating from around Memorial Day through late September. There may be additional closures when construction starts (see below).
Directions: From Boulder, it’s easy. Just take Flagstaff Road west until it turns into eastern Gross Dam Road.
Gross Reservoir was finished in the mid-1950s. It wasn’t until recently that it opened up for public paddling. The reservoir is water storage and also regulates water flow below the Continental Divide.
The east side of the reservoir is owned and operated by Denver Water. The west side is managed by the Roosevelt National Forest’s Boulder District. That’s the side you want to keep in mind for camping.
The reservoir was named after Denver Water’s former chief engineer Dwight D. Gross.
There’s a project to expand the reservoir for the future. It would raise the level of the dam by 131 feet, making it the tallest dam in the state (as well as the largest public works project in Boulder County history). Construction is expected to be done around 2025. The project is controversial, though, because it would mean removing many trees.
Here are some of the ways you can use Gross Reservoir.
Fishing: The Colorado Division of Wildlife stocks the reservoir with cold-water fish (rainbow trout, brown trout, lake trout, splake, kokanee salmon and tiger muskie). The best places to fish are below the dam, near the inlet and within the body of water. You can also fish off much of the shore. You can ice-fish here in the winter when conditions permit.
Picnicking: Gross Reservoir has four different picnic areas: North Shore, South Shore, Miramonte and Windy Point. Find restrooms, parking and sheltered picnic tables on the east side of the water. This side of the lake is for day use only. The reservoir is big enough that you can likely eat in privacy.
Hiking: There are several hiking options here. Take the North Point picnic area to get to the reservoir. Follow the South Shore Recreation Area trailhead to the South Boulder Creek Inlet.
One fun hike in this area is to take the Forsythe Canyon to the waterfall and end at the reservoir. This two-plus-mile round-trip hike is shady, rarely busy and easy-to-moderately difficult. It may be appropriate for kids. It’s pretty spectacular, with the small waterfall, wildflowers, the stream, canyon and ending with the alpine water. Find the Forsythe Canyon Trailhead from Lakeshore Road (not Magnolia Road).
Water access: No swimming, diving, wading or otherwise splashing. If you want to get in the water, you have to stay on the water, in a non-motorized boat. Stand-up paddleboarding is OK. Non-motorized boats (like canoes and kayaks) are permitted in late May through the end of September, sunrise to sunset. Leave your sailboat, trailer-hitched boat and motor boat at home.
Paddling can be challenging here due to the wind spilling off the Continental Divide. And the water is frigid. The reservoir is remote and has limited facilities, so come prepared. Weather can change quickly and get extreme.
If you’re still up for it, the views and solitude can be worth it, especially if you find your way into one of the private, little fingers of the lake.
The boat put-in is on the south shore at Osprey Point.
In the winter, some people go ice-skating here, but it’s done at your own risk. It can get really windy here, and the sharp wind plus icy conditions can be rough.
Bouldering: You can find bouldering opportunities on the east side of Gross Dam Road, southeast of the water.
Yes, you can camp. But it’s primitive. And only allowed on the west side of the lake in the Roosevelt National Forest.
This area has about 20 campsites scattered throughout the trees. They’re all marked with a number and have a fire ring, although fires may not be permitted. You must currently keep fires in grills and fire grates. (There was a small wildfire near the reservoir in June. No cause was released.)
Camping is free and there are no reservations. It’s first come, first served. You can camp from Memorial Day until the first snowfall; campsites are closed seasonally. Before heading out, check with the Boulder District to make sure conditions are safe and it’s open.
You will need a high-clearance vehicle to get access to this area via a bumpy dirt road on the west side. Take Magnolia to Colo. 68 and take that to Forest Service Road 359. There is no access from the east side (on Lake Shore Drive), no matter what Google Maps insists. It’s lying.
You cannot camp on Denver Water’s side of the reservoir.